Gas burner ignition system



June 26, 1956 P. l. HOLLMAN 2,751,976

GAS BURNER IGNITION SYSTEM Filed Jan. 19, 1952 ---'t.:: k 23 I I v g /2 50 l f 77 /772 677 or W n i PM ,0, 22 z z 2 q W MJL United States Patent 6 GAS BURNER IGNITION SYSTEM Peter I. Hellman, Rockford, IlL, assignor to Geo. D. Roper Corporation, Rockford, 111., a corporation of Illinois Application January 19, 1952, Serial No. 267,288

Claims. (Cl. 158-130) This invention relates to an ignition system for gas burners, and in particular to an oven lighting system for gas stoves.

It is an object of this invention to provide an oven lighting system in which there is a safety valve thermostatically controlled by an ignition pilot burner for the oven burner and in which an auxiliary gas supply is established to the oven burner as long as the safety valve remains open, which is independent of the main shut-01f valve for the oven burner.

Another object of the invention resides in the provision of an auxiliary gas supply to the oven burner which bypasses the main shut-off valve for the oven burner to maintain a stand-by flame on the oven burner for a time interval following the closing of the main shut-off valve, in order to insure the immediate lighting of the main gas supply to the oven burner, should the main shut-oflf valve be opened in that time interval.

Other and further objects and advantages of the invention will be apparent from the following description of one embodiment thereof, which is shown in the accompanying drawing to illustrate the principles of the invention.

In the drawing:

Figure l is a top view of the oven burner ignition system of the present invention;

Figure 2 is a front View, partly in section, showing the flash tube and pilot burner arrangement for igniting the oven burner from the constant top pilot burner on a gas stove; and

Figure 3 is a longitudinal cross-section through the safety valve included in the system of the present invention.

Referring to the drawing, the disclosed form of the invention, in its broad outline, includes an oven burner 11, an ignition pilot burner 12 for lighting the oven burner, a top pilot burner 13 (Fig. 2) for lighting the ignition pilot burner through the flash tube arrangement 14, and an oven control valve 15 and a push-button safety valve 16 for controlling the gas supply to the oven burner.

The gas supply for the oven burner is from a manifold 17, which extends across the front of the stove at the top thereof. The oven control valve 15 is mounted on the manifold 17 to receive gas therefrom and is manually operated between its closed and open positions by means of the manual control knob 18. Preferably, this oven control valve is of the type shown in U. S. Patent 2,303,011, to which reference may be made for a more complete description of its construction and mode of operation. Suflice it to say that, when the control knob 18 is turned clockwise, gas is passed through oven control valve 15 to the conduit 19 leading to the ignition pilot burner 12 and to the conduit 20 for the oven burner leading to safety valve 16. As is well known in oven control valves of this type, the supply of gas to the oven burner conduit 20 is controlled thermostatically in response to the oven temperature, as by a temperature responsive bulb (not shown) connected to the control 7 button 46. Then, when the inward force on the push but;

valve 15 through a tube 15a, while the gas supply to the ignition pilot burner 12 is independent of such thermostatic control.

From conduit 19 the gas supply to the ignition pilot burner passes through an extension conduit 21 leading to a cylindrical fitting 22. The latter carries a top plate 23 formed with passages 24-leading to the vertical flash tube assembly 25. At its upper end the vertical flash tube communicates with a horizontal flash tube 26 leading to the upper, constantly burning pilot burner 13 at the top of the stove.

The ignition pilot burner 12 in this instance is in the form of a substantially U-shaped horizontal tube, which is threadedly received in a passage in the side of the member 22. The ignition pilot burner 12 is formed with a series of flame ports 27 at its upper side. A thermocouple 28 is mounted to extend above the flame ports and is suitably electrically connected through line 29 to the winding 30 of an electro-magnet 31 in the safety valve 16.

In the lighting of the ignition pilot burner 12, when the control knob 18 is turned to open the oven control valve 15, gas is supplied to the fitting 22 for passage to the pilot burner 12. Gas from the fitting 22 also rises through the flash tube assembly 14 and is ignited by the top pilot burner 13, flashing back through the flash tube assembly to ignite the gas issuing at the flame ports 27 at the ignition pilot burner 12.

As best seen in Fig. 3, the safety valve 16 has two inlets: One, from conduit 20 leading from oven control valve 15, and the other from bypass conduit 32 leading directly from manifold 17. Both of these conduits communicate with an inlet chamber 33 in the safety valve.

From the safety valve outlet chamber 34 the gas flows' 38 to seat at the inlet end of the passage 39, which extends between the inlet and outlet chambers 33 and 34 in the safety valve 16. The stem 40 for valve 37 carries at its opposite end an armature 41 which is located in a chamber 42 sealed from the gas inlet chamber 33 in the safety valve.

Within the outlet chambers '34 of the safety valve there is disposed another valve closure member 43, which is biased by coil spring 44a toward seating engagement at the discharge end of the valve passage 39. A re'ciprocable stem 44, which extends slidably through valve member 43, carries an enlarged transverse head 45 at its inner end which engages the inner face of the'valve closure member 43. At

stem 44 retracted. The force of spring 47 overcomes the force of spring 44a, so that valve closure member 43 is normally maintained retracted away from engagement with its seat at the discharge end ofvalve passage 39.

In the operation of the safety valve 16, valve member 37 is normally maintained by spring 38 seated against the inlet end of passage 39 to prevent the flow of gas from the inlet conduits 20 and 32 to the outlet conduit 35 leading to oven burner 11. After the oven control valve 15 has been opened, the operator depresses push-button 46 against the force of spring 47. The head 45 on stem 44 engages the head 48 on valve member 37 to retract the latter away from its seat. At the same time, spring 44a moves the other valve closure member 43 to block valve passage 39 at the discharge end thereof, to maintain the outlet conduit 35 blocked from communication with the inlet conduits 20 and 32 to the safety valve 16. If the electromagnet 31 has been energized sufiiciently, it holds armature 41 to maintain valve 37 in its retracted position to which it has been moved by depressing the push- Patented June 26, 1956 .which it is held bythe electromagnet.

r 3 ton is released, valve closure member 43 is returned by spring 47 to its normal position away from the discharge end of valve passage 39.

With'the safety valve '16 thushaving been opened gas is supplied: to oven burner 11 from the oven control valve 15, and through bypass conduit 32 directfrom mani fold 17. a

The oven burner 11 carries a lateral tube 49 which is.

mit'th ermocouple 28 to be heated by pilot burner 12 for energizing electromagnet 3-1 push button 46 is then depressed to push. valve member 37 to its open position, at While the push button is depressed, valve member 43 maintains the safety valve 16 closed. Upon release of the push button, the safety valve 16 remains open as long as thermocouple 28 is heated by ignition pilotburner 11.

When the oven control valve is closed, the main gas supply to the ignition pilot burner 11 is shut oif and the thermocouple 28 cools down to tie-energize electromagnet 31, which releases armature 41 to permit valve member 37 to close safety valve 16; Since there is a certain time delay involved in the closing of the safety valve 16, due to residual baking heat in the oven which prevents the thermocouple 28 from cooling rapidly, it is desired to maintain a stand-by flame or oven burner 11 as long as the safety valve is open, so that, if the oven control valve should again be opened before the safety valve has closed, there would be no discharge of unign'i-ted raw gas issuing from the oven burner. The gas supply through conduit 32 direct from manifold 17 is passed to the oven burner 11 as long as the safety valve 16 is open, independent'of the oven control valve 15.

A certain portion of the stand-by gas supply through conduit 32 is passed through conduit 20 and back throughoven control valve 15 to the ignition pilot burner 12 to maintain a stand-by name on the pilot burner as long as safety valve 16 is open. A throttling valve 51 may be provided in conduit 32 to limit the gas flow therethroug'h so that the level of the stand-by flame on pilot burner 12 is insuflicient to heat thermocouple 28 to maintain electromagnet- 31 energized. Alternatively, the oven control valve 15 may be so constructed asto prevent the reverse flow of gas therethrough from the outlet conduit 20 and through conduit 1-9 to pilot burner 12 while the oven. control valve 15 is closed.

While in the foregoing description there is disclosed a specific embodiment of the present invention, it is to be understood that various changes, omissions, refinements and modificationsdeparting from the described form of the invention may be adopted without departing from' of a main gas burner,- a supply line connecting the main burner to a gas supply, main shut-off valve means the gas supply line to the main: burner operative when open to permit the supply of gas thereto, normally closed safety valve means connected in the gas supply line to the main burner between the main shut-off valve and the mainburner controlling the new" of gas" thereto operative when close'd to block the flow of gas to the main burner and o erative'when open to permit the supply of gas' thereto, an ignition pilot burner in igniting relation to the main burner operative to be lighted when said main shut-off valve means is opened, heat respo'nsivemeans positioned in heat receivingrelation to said pilot burner and op eratii/e when heated sufiicienfly thereby to maintainsaid safety verve means opento permit the" new of as there-- supply line to the oven burner operative when open to, 7

permit the supply of gas thereto, normally closed safety valve means connected in the gas supply line to the oven burner between the main shut-off valve and the oven burner controlling the flow of gas thereto, an ignition pilot burner in igniting relation to the oven burner operative to be lighted when said main shut-01f valve means is opened, heat responsive means positioned adjacent said pilot burner and operative when heated sufficiently thereby to maintain said safety valvemeans open to permit the flow of gas to the oven burner, and by-pass conduit means leading to said safety valve means directly from said gas supply for the oven burner operative to supply gas tot-he oven burner through the safety valve means independent.

of said main shut-off valve means as long as'said safety valve remains open. V

3. In an oven lighting system for gas stoves, the combination of an oven burner, a gas supply line connecting the oven burner to a gas supply, a manually operated main shut-off valve in the gas supply line to the oven burner operative when open to permit supply of gas thereto and operative when closed to block the supply of gas thereto,- a normallyclosed safety valve in the gas supply line to the oven burner after, said main shut-off valve controlling the flow of gas to the oven burner, an ignition pilot burner in igniting relation to the oven burner operative to be lighted in response to the opening of said main shut-off valve, heat responsivemeans positioned adjacent said pilot burner and operatively connected to said safety valve to maintain the latter open when heated sufficiently by said pilot burner, to permit the flow of gas to the oven burner, and a by-pass conduit communicating with said safety valve and connected to the gas supply line for the oven burner ahead of said main shut-off valve operative to supply gas to the oven burner through the safety valve independent of said main shut-off valve as long as said safety valve remains open. 7

4. In a gas burner lighting system, the combination of a main gas burner, a gas supply line connecting the oven burner to a gas supply, main shut-off valve means in the gas supply line to the main burner operative when open to permit the supply of gas thereto, normally closed safety valve means in the gas supply line to the main burner between the main shut-off valve and the oven burner controlling the fiow of gas thereto, thermal responsive means operably connected to said safety valve means and opera: tive'when heated to a preselected temperature to hold said safety valve means open, a pilot burner operative to main tain a flame in heat transmitting relation to said thermal responsive means to heat the latter to said preselected temperature while said main shut-off valve means is open,- and by-pass conduit means connected to said safety valve means directly from said gas supply for the main burner operative to supply gas to'the'main burner through the safety valve means independent of said main shut-off valve means as long as said safety valve means remains open.

5. In an oven lighting system, the combination of an oven burner connected to a gas supply, a manually controlled'main shut-01f valve in the gas supply line to the oven burner operative when open to permit the supply of gas thereto, a normally closed safety valve in the gas supply line to the oven burner controlling the flow of gas thereto operative when closed to block the flow of gas to the oven burner and" operative when open to permit are when heated siiiflciently to hold said safety valve open, a

W 2,751,976 5 6 pilot burner adjacent said thermal responsive means operconduit means for throttling the flow of gas therethrough ative to maintain a flame in heat transmitting relation to maintain a reduced level flame on said oven burner. thereto to heat the same sufiiciently to maintain the safety valve open while said main shut-01f valve is open, by-pass References Cited in the file of this patent conduit means communicating with said safety valve di- 5 UNITED STATES PATENTS recfly from sa1d gas supply for the oven burner operative to supply gas to the oven burner through said safety valve 2,483,191 Gilugel' P 1949 independent of said main shut-01f valve as long as said 2,506,403 W1t'Zel May 2, 1950 safety valve remains open, and means in said by-pass 2,557,927 Abrams June 26,1951 

